As of maven-javadoc-plugin 3.0.0 you should have been using additionalJOption to set an additional Javadoc option, so if you would like Javadoc to disable doclint, you should add the following property.
<properties>
...
<additionalJOption>-Xdoclint:none</additionalJOption>
...
<properties>
You should also mention the version of maven-javadoc-plugin as 3.0.0 or higher.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>3.0.0</version>
</plugin>